PubMed Health⌕ Search

Biomedical subjects

Shweta Mahajan

Publications and source records attributed to Shweta Mahajan.

4 recordsLinked to original sources

A new synthetic protocol for labeled oligonucleotides, using a chemically cleavable universal linker.

A two-step general method for labeling of synthetic oligonucleotides is described. The protocol employs a cleavable universal linker, 5'-O-(4,4'-dimethoxytrityl)-3'-O-benzoyl-2'-O-(2-cyanoethyl-N,N-diisopropyl)-uridine phosphoramidite, to effect coupling to polymer-bound oligonucleotide chains. Sequentially, coupling with commercially available phosphoramidite reagent of an appropriate label (Biotin, HEX etc.) in an automated DNA synthesizer is carried out. The labeled oligomers, obtained after cleavage and deprotection reactions, are analyzed on RP-HPLC. A distinctive feature of this protocol is the recovery of free oligomers from their labeled analogs under mild conditions. The oligomers obtained are comparable to the corresponding standard oligonucleotides (HPLC).

Biotin↗

Spectrophotometric estimation of functional groups on microslides for preparation of biochips.

A universal reagent 1-O-(4,4'-dimethoxytrityl)-6-aminohexanol (DTAH) is described for the estimation of surface-bound functionalities (epoxy, aldehyde, and carboxyl) required for preparation of oligonucleotide arrays (biochips). The method involves the reaction of universal reagent DTAH with surface-bound functionality under microwaves for 10 min, followed by washings to remove the excess reagent. In the subsequent step, a weighed amount of DTAH-treated surface is exposed to acid to liberate 4,4'-dimethoxytrityl cation, which is measured at 505 nm to determine the functional group loading on the surface.

Aldehydes↗

Universal reusable polymer support for oligonucleotide synthesis.

A new efficient reusable universal polymer support for oligonucleotide synthesis, based on a non-ammoniacal cleavable linker, is described. Twenty six cycles of oligonucleotide synthesis have been carried out without compromising the quality of the fully deprotected oligonucleotides.

Chromatography, High Pressure Liquid↗